This from Peter Wadhams, one of the first people to discover the shrinkage of the ice caps.
https://www.theguardian.com/environment/2016/aug/21/arctic-w...
"As far as I can see, it will have to take the form of some sort of device into which you pump air at one end and you get air without carbon dioxide coming out the other end. It can be done, I am sure, but at the moment we do not have such a device. However, without something like that I cannot see how we are going to deal with the carbon dioxide that is getting into the atmosphere. We are going to have to rely on a technology that has not yet been developed. That is a measure of the troubles that lie ahead for us. I think humanity can do it, but I would feel much better if I saw governments investing in such technology."